HIV genome structure decoded

It might not be super high-res, but researchers at the University of North Carolina at Chapel Hill have described the first full structure of the HIV-1 genome.

The paper, published online today in Nature, maps out the virus' genome down to a one-nucleotide resolution with the help of a technique call SHAPE—selective 2'-hydroxyl acylation analyzed by primer extension—to paint the full, previously unknown picture of the virus (Scientific American is part of Nature Publishing Group).

"The technique is thus akin to zooming out on a map and getting a broader view of the landscape at the expense of fine details," writes Hashim Al-Hashimi, of the University of Michigan in Ann Arbor, in the accompanying views piece.

Like viruses such as the common cold and hepatitis C, HIV (the human immunodeficiency virus) is made up of single-stranded RNA that folds into a convoluted architecture. Previous studies have focused on various parts of HIV, but the new research presents the bird's-eye-view of the full genome. "The study … is a considerable achievement, showing the feasibility of obtaining 'aerial' views of large genomic RNA structures that reveal their architecture and possible functions," Al-Hashimi writes.

The new map will help researchers pinpoint different functions of the RNA as well as the virus' progression—all of which, scientists hope, will lead to better treatment in the future.

"There is so much structure in the HIV RNA genome that it almost certainly plays a previously unappreciated role in the expression of the genetic code," Kevin Weeks, lead study author and professor of chemistry at the University of North Carolina, said in a prepared statement.

"We are also beginning to understand tricks the genome uses to help the virus escape detection by the human host," said Weeks.